The surveys show marks made when crops growing over buried features develop at a different rate from those nearby.
The newly-discovered Roman and prehistoric settlements include a site near Bradford Abbas, Dorset.
The Roman camp was revealed in June after three sides became visible in sun-parched fields of barley.
The lightly-built defensive enclosure would have provided basic protection for Roman soldiers while on manoeuvres in the first century AD and is one of only four discovered in the south west of England, English Heritage said.
The dry conditions also allowed well-known sites to be photographed in greater detail.